1. National Field of Invention
One version of the voltage indicator is intended for single-phase and three phase AC voltage detection on 90-277 volt (with respect to ground) rms wires enclosed in metal conduit as is used in grounded AC power distribution systems as is common in the United States.
2. International Field of Invention
Another version of the voltage indicator is intended for single-phase and three phase AC voltage detection on 90-277 volt (with respect to ground) rms wires enclosed in metal conduit as is used in grounded AC power distribution systems as is common outside the United States.
3. Reasons for Utility of Invention
This invention shows that voltage is present on at least one wire of possibly several that are enclosed in a section of metal conduit of various possible sizes. The electrically isolated section of conduit is grounded to the rest of the metal conduit system through two opposing rectifiers which will electrically break down if a “hot” wire grounds to this semi-grounded section of the conduit.
1. Device can be mounted anywhere during initial installation in metal conduit system where there are two or more feet of exposed metal conduit.
2. Device doesn't physically damage the enclosed wiring.
3. Circuit breaker or fuse may be tripped or blown at main panel.
4. Incandescent light bulb filament may be burned out.
5. Ground fault circuit interrupter may be tripped.
6. Receptacle may be controlled by a light switch.
7. The circuit breaker panel is at a remote location.
8. The load may be burned out or defective.
9. The load may consist of a heating or cooling device that would take several minutes to know if turned on.